.net-core - .net Core 3.0 预览版 2 - [406 : Not Acceptable]

Question

我基于 Microsoft 文档使用 Microsoft 2.2 构建了一个 Web API。
一切都按预期进行。

更新到 .net Core 3.0 Preview 2 后，所有端点都返回 [406: Not Acceptable]。

缺少一些东西，但到目前为止我无法理解缺少什么。以下代码与 .net core 2.2 相同。

程序.cs

public class Program
{
    public static void Main(string[] args)
    {
        CreateWebHostBuilder(args).Build().Run();
    }
    public static IWebHostBuilder CreateWebHostBuilder(string[] args)
    {
        return WebHost.CreateDefaultBuilder(args)
            .UseStartup<Startup>();
        //.ConfigureKestrel((context, options) => { });
    }
}

Startup.cs

public class Startup
{

    public void ConfigureServices(IServiceCollection services)
    {
        // Dependency Injection - Services
        services.AddSingleton<IXXXService, XXXService>();

        services.AddMvc();

        services.AddCors(options =>
        {
            options.AddPolicy("AllowAll",
                builder => builder.WithOrigins("*").AllowAnyHeader().AllowAnyMethod());
        });

        services.AddSwaggerGen(c =>
        {
            c.SwaggerDoc("v1", new OpenApiInfo { Title = "My API", Version = "v1" });
            c.EnableAnnotations();
        });
    }


    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        app.UseMvc();
        app.UseCors("AllowAll");

        app.UseSwagger();
        app.UseSwaggerUI(c => { c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API"); });
    }
}

XXXController.cs

[ApiController]
[Route("api/xxx")]
public class XXXController : BaseController
{
    private readonly IXXXService _service;

    public XXXController(IXXXService service)
    {
        _service = service;
    }

    [HttpGet]
    [Produces("application/json", Type = typeof(PagedDto<XXX>))]
    [SwaggerOperation(
        Summary = "Gets all the XXX",
        Description = "Requires admin privileges",
        OperationId = "GetAllXXX",
        Tags = new[] {"XXX"}
    )]
    public IActionResult GetAllXXX([FromQuery] PagingDto pagging)
    {
        return Ok(_service.GetAllXXX(pagging));
    }
}

Answer 1

我在 Microsoft github 上发布了这个问题，这是他们的回应:

You have to install the nuget package Microsoft.AspNetCore.Mvc.NewtonsoftJson
In your startup.cs file, add the JsonFormatter like this :

services.AddMvc().AddNewtonsoftJson().SetCompatibilityVersion(CompatibilityVersion.Version_3_0);
通过此更改，一切都按预期进行。